We are taking two complementary approaches to examining the molecular basis and functional significance of the increased rate of hexose transport in chicken embryo cells transformed by Rous sarcoma virus. In the first approach, we manipulate one parameter of the "transformed phenotype" (using physiological or genetic techniques) and study the effcts on other manifestations of malignant transformation. In the second approach, we identify, purify and characterize a protein which displays glucose-specific cytochalasin B binding, and utilize this information to analyze the regulaton of hexose transport at the molecular level.